This page provides information about the Surface Luminance utility texture in V-Ray for Blender.


Overview

V-Ray's extra attributes for the Surface Luminance node allow control of luminance calculation.

The most common workflow for the Surface Luminance node attributes is to connect the node to a floating texture input slot of a V-Ray ExtraTex render channel. This allows you to control the Luminance mode shown in the ExtraTex channel.


UI Path: ||V-Ray Node Editor|| > Shader > Add > Texture Utilities > V-Ray Surface Luminance


Properties


Luminance Mode – Controls how luminance is calculated.

No luminance – No luminance is calculated.
Direct light – Calculates luminance from direct lighting. It creates a grayscale mask over the points of objects lit by direct lighting.
Diffuse light – Calculates luminance from indirect lighting (GI). It creates a grayscale mask over the points of objects lit by indirect lighting. 
Direct+diffuse light – Calculates luminance from direct and indirect lighting. This creates a grayscale mask over the points of objects by direct and indirect lighting.
Matte Shadow –  Creates a grayscale mask over all shadowed points of objects. Unlike the standard Matte Shadow render channel, this mode creates a two-sided mask covering both the lit and unlit points of the objects.

Samples – Specifies samples for diffuse lightning.

Contribute To GI – When enabled, the direct light contributes to the GI calculations. The effect is visible only when the texture is used for diffuse calculation with either the Diffuse Only or the Direct+diffuse light mode.